Process for treating papermakers&#39; felt and products obtained therefrom



United States Patent 7 3,292,992 PROCESS FOR TREATING PAPERMAKERS FELT AND PRODUCTS OBTAINED THEREFROM Arthur E. Manasian, Newfane, N.Y., assignor to Huyck Corporation, Stamford, Conn., a corporation of New York No Drawing. Filed Dec. 18, 1962, Ser. No. 245,393 13 Claims. (Cl. 8127.6)

This invention relates to a process for treating protein materials and to the product resulting threfrom, and more particularly relates to a process of treating wool and to the product resulting therefrom.

Wool and other protein material may be modified to advantage using precondensates of polyhydric phenols and formaldehyde. Also protein materials, particularly leather, can be modified with water-soluable or solventsoluble condensation products of phenols and aldehydes. Dihydroxy and trihydroxy derivatives of benzene and their substitution products can be used effectively with aldehydes to modify proteinaceous materials. Monohydric phenols having sufficient reactivity will combine with formaldehyde and wool resulting in a weight increase and some change in properties of the wool. However, the known reactants which produce the desired improvements in properties also adversely affect the color of the treated protein material. The color may be imparted to the material when heated or may arise after use or upon exposure to heat or light.

The known processes using phenolic resins for shrinkproofing or applying wash and wear treatment to woolen clothing and other fabrics result in undesirable discoloration of the material treated. The present invention imparts only a light cream color to the material which is not objectional for most purposes.

The present invention is particularly applicable to I papermakers felts. A papermakers felt is a woven fabric, usually wool, which is usually fulled after weaving to form a firm fabric of specific desired dimensions. Having been fulled to predetermined dimensions, it is essential to the successful use of the felt that it maintain those dimensions as closely as possible. Such felts are employed to convey wet paper from a web forming device to and through apparatus used in the paper-making process. The felt is subject to much abrasion and chemical action in use and has a relatively short life. the felt have high tensile strength because it is subject to much stress and stretching in the paper making apparatus. The felt must have a high degree of porosity to allow water to drain freely through the felt as it passes through the various paper making steps. The felt must be easily cleanable because the felts tend to fill up with foreign matter and small fibers of pulp which must be regularly removed. Satisfactory drainage of water from the Wet pulp must be maintained so that the speed of the paper making process is not reduced of insuflicient Water removal from the wet pulp. To meet all of these requirements, the wool fibers used in papermakers felts must be chosen without regard to cost. Thus, the life of the felt is a substantial factor in the cost of producing paper and other articles made from wet pulp.

Small particles breaking off of the felt will frequently find their Way into the resultant paper product. If the felt is colored such particles will be readily apparent in or on a white paper; hence, it is desirable that the felt be white or light cream colored. The various phenolic treatments which have been used to increase the physical and chemical properties of papermakers felt usually have the undesirable side eflect of discoloring the felt.

It is an object of this invention to provide a process for improving the physical and chemical properties of proteinaceous material.

It is essential that I ice It is a further object of ths invention to provide a process of treatment which modifies proteinaceous material to impart increased dimensional stability, wearresistance, bacterial resistance, chemical resistance, and the like, without imparting undesirable color to the material.

It is another object of this invention to provide a proteinaceous product which has improved physical and chemical properties including stretch resistance, wear resilitance, bacterial resistance, chemical resistance, and the li e. i

It is still another object of this invention to provide a wool product which has improved physical and chemical properties and a light cream color.

Other objects will be apparent to those skilled in the art from reading the following description.

The objects of this invention are achieved by treating a proteinaceous material with 4-acetyl resorcinol and formaldehyde. The 4-acetyl resorcinol, which may also be identified as 2,4-dihydroxy-acetophenone, has a structural formula as follows:

This invention is applicable to all proteinaceous ma terials, including keratinous materials and natural fibers, such as wool, silk, hair, fur, feathers, leather and the like, and synthetic fibers, including those prepared from natural proteins such as zein, casein, soybean protein, fish proteins and the like. I

It has been found that 4-acetyl resorcinol will react with protein materials through an aldehyde intermediate. It has further been found that the 4-acetyl resorcinolformaldehyde reaction product is capable of producing significant improvements of an unexpected degree in protein material. Most surprisingly, 4-acetyl resorcinol'and formaldehyde are capable of producing the improvements without adversely affecting the color of the material. The latter advantage is particularly unexpected because the products formed by condensing resorcinol derivatives and formaldehyde with protein are expected by those skilled in the art to be colored. It has been found that there is an increase in weight of the protein fiber which is not readily removable by extraction with solvents in which resorcinol-formaldehyde condensates are normally soluble. It is preferred that the reactants be employed simultaneously and in their free and uncombined state in treating the protein material. The desirable improvements in the protein material are not obtained if the 4-acetyl resorcinol and formaldehyde are afforded time to react substantially or to any significant degree with each other prior to the addition of the protein material. It-is preferred to use the reactants within about one-half hour after mixing. In practice it is possible to successfully treat the protein material for one hour or more after mixing the reactants.

This invention relates primarily to the treatment of protein fibers to cause chemical modifications sothat in an atmosphere of high humidity, the treated protein fiber behaves much like a dry fiber. When completely saturated with water the treated fiber has increased resistance to extension.

' A fabric made from treated fibers has significantly increased wear resistance as measured by conventional laboratory testers, such as the Instron Tester, or by practical use. Treated fibers, such as wool, also have improved resistance to size increase under applied stress and improved resistance to size decrease caused by felting. The microbiological resistance of treated fabric is greater than-that of untreated fabric.

Patented Dec. 20, 1966 temperatures, such as from about 100 to about 212 F.

In treating wool, however, it is preferred to carry out the reaction at temperatures between about 140 F. and 212 F.

After an improvement of about 20% in the work index has occurred, additional reaction time will not significantly change the properties of the modified product. Treatment is substantially complete in about one hour. Treatment with the solution of 4-acetyl resorcinol and formaldehyde for more than about an hour does not effect further significant improvement in properties. It has been found that treatment for about one hour at about 165 F. yields the best results.

The pH of the treating solution may be varied widely, such as from about 2 to 9. If the pH is below about 2, or above about 9, some proteinaceous fibers tend to decompose. A pH between 4.5 and 7.0 has been found particularly satisfactory. The preferred pH range is from 5.5

to 7.0. In practice, a pH of about 5.5 results from the use of 4-acetyl resorcinol without an added buffer.

Wide ranges of reactant concentrations and reactant ratios may be used. The preferred limits of 4-acetyl resorcinol concentrations are between about 0.02 and 0.10 moles perliter (M). It has been found that above a concentration of about 0.08 mole per liter, little improvement in the properties of treated material is observed.

The molar ratio of formaldehyde to 4-acetyl resorcinol has been varied from 1:2 to 4: 1. Higher ratios of formaldehyde tend to produce a tensilely weaker product than low concentrations. In practice, it is preferred to use 8. formaldehyde to 4-acetyl resorcinol molar ratio of about 2:1.

The treating solution to protein volume ratio may be varied from 0.6:1 to 50:1. However, it is perferred that the ratio be maintained between about 8:1 to 40: 1. Best results have been obtained with a solution to protein ratio of about 16 to 1.

It 'has been found that high temperature curing is not necessary. The reactions are complete when the fabric leaves the reaction mixture. However, temperatures up to 250 F. may be used to speed drying.

The treated product is heavier than the starting protein material. The resulting weight increase rises as the availability and concentration of 4-acetyl resorcinol increase. The maximum effective weight increase is about 20% at a 4-acetyl resorcinol molar concentration of 0.08 mole per liter using a 16:1 solution to protein ratio. Weight increases beyond about 20% do not result in a significan improvement in properties.

The process may be used to modify a mixture of protein fibers or a mixture of protein and non-protein fibers. Because the reaction modifies only the protein fibers, the treatment may be employed on fabric containing synthetic and other natural fibers without regard to the percentage of protein fiber in the fabric. If however, the fabric contains fibers, such as nylon, which react with one or more of the reactants, due consideration must be given to such reaction in order that a proper level of modification of the protein fiber is reached. Fabrics containing at least 25% proteinaceous material, preferably wool, and up to 75% of a synthetic, such as nylon or Dacron (polyester fiber), by weight, have been treated with no evidence of'a limit having been reached, while observing the foregoing cautions. Fabrics, such as for papermakers felts, containing at least about 25 wool, provide a suitable capability of fulling and felting and, when treated in accordance with the invention, have enhanced resistance to wear, microbiological attack, and other enhanced properties over those of the untreated fabric. Those fabrics containing at least about 40% wool are particularly enhanced in their properties by the treatment of the inven-.

tion.

Nylon will react with the 4-acetyl resorcinol and aldehyde reactants, and therefore sufiicient amounts of, re-.

actants are desirably employed to react with it. Other synthetics, such as polyester fibers, react only slightly, if- 1 r at all, and when employing such synthetics, little or none. 1

of the reactants are needed to react with the synthetic component of the substrate.

The preferred conditions for treatment involve the use of concentrations of 0.06 mole of 4acetyl resorcinol and 0.12 mole of formaldehyde in aqueous solution at a pH of 6.8, with the treatment being carried out for one hour at about 165 F.

In order more clearly to disclose the nature of the present invention, specific examples of the practice of the invention are hereinafter given. Itshould be understood, however, that this is done solely by way of example and is intended neither to delineate the scope of the invention nor limit the ambit of the appended claims.

Example I Into 1600 parts of water at 165 F. were dissolved 14.6 parts of 4-acetyl resorcinol. The solution was buffered to a pH of 6.8 by adding 2.5 g. of monosodium phosphate and 1.5 g. of disodium phosphate. To the buffered solution were added 5.7 parts of formaldehyde.

Into the resulting solution were immersed parts of a individual fibers had increased by 17-18%.

Example If Into 1600 parts of water at F. were dissolved 14.6 parts of 4-acetyl resorcinol. The solution was buffered to a pH of 6.8 by adding 2.5 g. of monosodium phosphate and 1.5 g. of disodium phosphate. To the resulting solution were added 5.7 parts of formaldehyde.

Into this treating solution were immersed 100 parts. of

woven fabric containing 50% wool and 50% nylon. The

fabric was treated for one hour at 165 F. with mild agi After one hour the fabric was removed from tation. the solution, rinsed with warm water and dried. Upon analysis the fabric was found to have a weight increase of 8%.

Example III The experimental procedure of Example II was repeated except that 100 parts of woven fabric containing 50% Wool and 50% polyester fiber were immersed inthe treating solution for one hour at 165 F with mild agitation. weight increase of 7.1%.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expres sions, of excluding any equivalents of the features shown and described or portions thereof, but it is recognized i that various modifications are possible within the of the invention claimed.

What is claimed is: Y 1. A process for treating proteinaceous material comscope prising immersing proteinaceous material in an aqueous.

solution of 4-acetyl resorcinol and formaldehyde, and drying said proteinaceous material, whereby the chemical and physical properties of the proteinaceous material are 1 improved.

Upon analysis the fabric was found to have a 2. A process for treating papermakers felts comprising immersing protein material in an aqueous solution of 4-acetyl resorcinol and formaldehyde, and drying said papermakers felts, whereby the chemical and physical properties of the papermakers felts are improved and a light cream color is imparted to the material.

3. A process for treating papermakers felts comprising dissolving 4-acetyl resorcinol in an aqueous solvent, adding formaldehyde in a ratio to said 4-acetyl resorcinol of between about 1:2 and 4:1, immersing the papermakers felts to be treated in the solution formed, and drying said papermakers felts, whereby the dimensional stability and bacterial resistance of said papermakers felts are increased.

4. A process for treating a papermakers felt comprising dissolving 4-acety1 resorcinol and formaldehyde in an aqueous solution having a pH between about 2 and 9, said formaldehyde being present in a ratio of 1:2 to 4:1 to said 4-acetyl resorcinol, heating said solution to between about 100 to 212 F., immersing the papermakers felt in said solution for about one hour while maintaining said temperature, and drying said papermakers felt, whereby the dimensional stability and bacterial resistance of the papermakers felt are increased.

5. A process for treating papermakers felts comprising dissolving 4-acetyl resorcinol and formaldehyde in an aqueous solvent having a pH of between about 5.5 to 7.0 and a molarity between about 0.02 to 0.10 based on said 4-acetyl resorcinol, said formaldehyde being present in a ratio of about 2:1 to said 4-acetyl resorcinol, heating said solution to between about 100 to 212 F., immersing the papermakers felts in said solution for about one hour while maintaining said temperature, and drying said felts, whereby the dimensional stability and bacterial resistance of the papermakers felts are increased.

6. A papermakers felt modified with the reaction product of 4-acety1 resorcinol and formaldehyde.

7. A papermakers felt comprising at least about 25% by weight of papermakers felt modified with the reaction product of 4-acetyl resorcinol and formaldehyde.

8. A woven woolen fabric modified with the reaction product of 4-acetyl resorcinol and formaldehyde.

9. A papermakers felt comprising a woven wool fiber base modified with the reaction product of 4-acetyl resorcinol and formaldehyde.

10. A papermakers felt comprising a woven woolen fabric consisting of substantially only wool modified with the reaction product of 4-acetyl resorcinol and formaldehyde.

11. A woven fabric containing at least about 25% by weight of wool and the remainder of synthetic fibers, modified with the reaction product of 4-acety1 resorcinol and formaldehyde.

12. A papermakers felt modified with up to about 20% by weight of the reaction product of 4-acety1 resorcinol and formaldehyde.

13. A papermakers felt modified with the reaction product of 4-acetyl resorcinol and formaldehyde and having a light cream color.

References Cited by the Examiner UNITED STATES PATENTS 1,713,641 5/1929 Bohm 8127.6 2,552,129 5/1951 Windus 8-l27.6 X 2,840,445 6/1958 Severn 894.24

OTHER REFERENCES Advances in Textile Processing, Lynn et al., editors, vol. 1, 1961, pp. 245-6.

NORMAN G. TORCHIN, Primary Examiner.

J. RAUBITSCHEK, Assistant Examiner. 

1. A PROCESS FOR TREATING PROTEINACEOUS MATERIAL COMPRISING IMMERSING PROTEINACEOUS MATERIAL IN AN AQUEOUS SOLUTION OF 4-ACETYL RESORCINOL AND FORMALDEHYDE, AND DRYING SAID PROTEINACEOUS MATERIAL, WHEREBY THE CHEMICAL AND PHYSICAL PROPERTIES OF THE PROTEINACEOUS MATERIAL ARE IMPROVED.
 9. A PAPERMAKERS'' FELT COMPRISING A WOVEN WOOL FIBER BASE MODIFIED WITH THE REACTION PRODUCT OF 4-ACETYL RESORCINOL AND FORMALDEHYDE. 